On the other hand, in this case, it seems we do have clues from the American end. There's a diary. This is the diarist
Seems reliable. According to the diary, John sr arrived with 6 kids. Wife not mentioned.
Find a matching family in Ireland and you're home and dry. Chances: not good.
Seems clear that no matching family in Ireland has actually turned up.
So people are in the process of creating a synthetic Irish family to fit the American data.
These things usually evolve. They get more concrete and detailed over time.
On WikiTree, John sr's father is also an immigrant. But the source link doesn't work.
Unlikely that John sr married in 1735 and immigrated in 1740 with 6 kids.